Saturday, November 1, 2008

Wallpapers, we don't need no stinkin' wallpapers

Wallpaper styles are as changing and various as people themselves, using photographs, drawings, 3D renders or abstract pattern with complex gradients. It can be helpful to have plain areas so that icons can be clearly seen atop the wallpaper.

Most common categories can include cars, models and celebrities, scenery, pets, movies, family, and personal photos.

When using rack mounted computers through a switch, it can often be useful to make a wallpaper with the computer's name on it, to easily identify which computer the user is connecting to.

System themes are often distributed with a background image that fits the style of the theme.

Oulets for programmers

An early screensaver for the Macintosh platform, and later PC/Windows, After Dark, prominently featured whimsical designs such as flying toasters. Perhaps in response to the workplace environment in which they are often viewed, numerous screensavers continue this legacy of whimsy by populating the idle monitor with animals or fish, games, and visual expressions of mathematics equations such as fractals.

The screensaver is also an outlet for the work of creative computer programmers. The Unix-based screensaver XScreenSaver collects the display effects of other Unix screensavers, which are termed "display hacks" in the jargon file tradition of US computer science academics. It also collects forms of computer graphics effects called demo effects, originally included in demos created by the demo scene.

Screensavers consume power?

Monitors that are running free screensavers consume the same amount of power as when running normally, which can be anywhere from a few watts for small LCD monitors to several hundred for large plasma displays. Most modern computers can be set to switch the monitor into a lower power mode. A power saving mode for monitors is usually part of the power management options supported in most modern operating systems, though it must also be supported by the computer hardware and monitor itself.

Additionally, using screensavers free with a flat panel or LCD screen instead of powering down the screen can actually reduce the lifetime of the display, since the fluorescent backlight remains lit and ages faster than it would if the screen was turned off completely. As fluorescent tubes age they grow progressively dimmer. A typical LCD screen loses about 50% of its brightness during a normal product lifetime. (In most cases, the tube is an integral part of the LCD and the entire assembly needs to be changed out)

Thus the term "screen saver" is somewhat a misnomer—the best way to save the screen (and also save electricity) would simply be to have the computer turn off the monitor.

Don't get your power management in a bunch.

Free Screensaver software can also be used as a rudimentary security measure. Many screensavers can be configured to ask users for a password before permitting the user to resume work. However, a user might be able to circumvent the password by restarting the computer if the computer's owner has set their account to automatically log in.

Screensavers are not to be confused with power management features. In fact, screensavers can actually waste power, because they can prevent the computer from entering the lower power (or sleep) state, and they often cause the CPU and GPU to perform more calculations, and keep the hard disk running for longer than if the computer were idle.

First Screensavers

The first free screensavers were allegedly written for the original IBM PC by John Socha, best known for creating the Norton Commander; he also coined the term screen saver. The screensaver, named scrnsave, was published in December 1983 issue of the Softalk magazine. It simply blanked the screen after three minutes of inactivity (an interval which could be changed only by recompiling the program).

The Atari 400 and 800's screens would also go through random screensaver-like color changes if they were left inactive for too long. The user had no control over this. These computers, released in 1979, are technically earlier "screen savers." And prior to these computers, the 1977 Atari VCS/2600 gaming console included color cycling in games like Combat or Breakout, in order to prevent burn-in of game images to 1970's-era televisions. These are examples of screensavers in ROM or the firmware of a computer.

Today with the help of modern graphics technologies there is a wide variety of different screensavers. Because of 3D computer graphics, which provide realistic environments, 3D screensavers are available.